US3825429A - Fogged direct-positive silver halide emulsion containing as stabilizer a bisulfite addition product of an aldehyde - Google Patents

Abstract

A DIRECT POSITIVE LIGHT-SENSITIVE SILVER HALIDE PHOTOGRAPHIC MATERIAL IS STABILIZED FOR STORAGE BY INCORPORATING THEREIN A POLYAMINE, A SALT OF A METAL MORE ELECTROPOSITIVE THAN SILVER AND A COMPOUND OF THE FORMULA

HO-(CH2)M-CH(-R)-SO3M

WHEREIN M IS 0 OR AN INTEGER OF 1 TO 8, R IS A HYDROGEN ATOM, OR AN ALKYL GROUP HAVING UP TO 17 CARBON ATOMS, OR AN ARYL GROUP AND M IS A CATION.

Description

United States Patent 3,825,429 FOGGED DIRECT-POSITIVE SILVER HALIDE EMULSION CONTAINING AS STABILIZER A BISULFI'IE ADDITION PRODUCT OF AN ALDEI-IYDE Tetsuo Furuya, Minami-Ashigara, Yoshio lbe and Hideo Kanisawa, Odawara, and Osakazu Sugino, Tokyo, Japan, assignors to Konishiroku Photo Industry Co., Ltd., Tokyo, Japan No Drawing. Filed Dec. 6, 1972, Ser. No. 312,493 Int. Cl. G03c 1/28, N34 US. Cl. 96-108 5 Claims ABSTRACT OF THE DISCLOSURE A direct positive light-sensitive silver halide photographic material is stabilized for storage by incorporating therein a polyamine, a salt of a metal more electropositive than silver and a compound of the formula HOCH CH-SO3M wherein m is 0 or an integer of 1 to 8, R is a hydrogen atom, or an alkyl group having up to 17 carbon atoms, or an aryl group and M is a cation.

This invention relates to a direct positive light-sensitive silver halide photographic material having improved storability.

When a light-sensitive silver halide photographic material is exposed to a light and then developed, the density thereof increases with increasing amount of exposure to reach the maximum value, in general. However, in case the amount of exposure is further increased, the density decreases again to finally form a positive image. Such phenomenon is ordinarily called solarization. The solarization phenomenon not only takes place due to excessive amount of exposure but also is observed in the case where a silver halide emulsion, which has previously been fogged opically or chemically during the course of preparation thereof, is subjected to ordinary exposure. By utilization of such phenomenon, therefore, it is possible to obtain a direct positive image. A light-sensitive silver halide photographic material, which has utilized the above-mentioned phenomenon, is generally called a direct positive silver halide photographic material, as is well known.

Ordinarily, a light-sensitive photographic material of this kind has previously been fogged chemically, and contains a silver halide photographic emulsion which has been incorporated with a fogging agent prior to completion of second ripening of the emulsion. Typical examples of the fogging agent used for the chemical fogging include aldehyde compounds such as formalin; sulfur compounds such as thiourea, thiourea dioxide and thiosinamine; basic nitrogen-containing compounds such as triethylenetetramine, ethylenediamine and ammonia; inorganic reducing agents such as stannous chloride; and salts of metals more electropositive than silver such as chloroauric acid, palladous ammonium chloride and platinic ammonium chloride.

However, direct positive light-sensitive silver halide photographic materials using the above-mentioned fogging agents have various disadvantages. For example, a silver halide emulsion fogged with the reducing agent is low in sensitivity, so that if the amount of light is small, no reversal phenomenon can be attained, and the minimum density is too high to provide the so-called clearness. On the other hand, if a basic nitrogen-containing compound is used as the fogging agent, the emulsion should be fogged at high pH and temperature. Accordingly, not only the preparation of the emulsion becomes difiicult but also the fogged nuclei obtained become low in stability to make 3,825,429 Patented July 23, 1974 the resulting photographic material unstable in photographic properties. Further, in case a salt of a metal more electropositive than silver such as chloroauric acid is used, there is the advantage that even a silver halide emulsion, which is relatively difficulty fogged, can be easily fogged. On the other hand, however, there are such disadvantages that the fogged nuclei formed are too strong to be destroyed by exposure and not only no substantial solarization takes place but also the resulting image is extremely lower in contrast.

Under such circumstances, many attempts have been made in order to overcome the abovernentioned disadvantages by use of various fogging agents in combination, but no satisfactory direct positive light-sensitive silver halide photographic materials have yet been obtained. Particularly the disadvantage of low storability of photographic material has been required to be overcome.

The present invention is concerned with a direct positive light-sensitive silver halide photographic material incorporated with (1) a fogging agent comprising a polyamine of the below-mentioned general formula (I) in combination with a salt of a metal more electropositive than silver, and (2) a compound of the below-mentioned general formula (II).

General formula (I):

wherein m is 0 or an integer of 1 to 8; R is a hydrogen atom, or an alkyl group having up to 17 carbon atoms or any aryl group; and M is a cation.

We have found that the above-mentioned photographic material is not only excellent in photographic properties but also can overcome the disadvantages of conventional photographic materials of this kind, as having such advantages that it is excellent in stability and thus is extremely less in variation in photographic properties even when stored over a long period of time, and that it can be prepared with ease.

The polyamine of the general formula (I) and the salt of a metal which is more electropositive than silver are preferably added at a step prior to completion of second ripening of silver halide emulsion. Generally, the polyamine is added in an amount of 1 to 200 mg., preferably 10 to mg., per mole of the silver halide, and the salt of a metal more electropositive than silver is added in an amount of 0.1 to 200 mg., preferably 1 to 100 mg, per mole of the silver halide, whereby the silver halide emulsion can be properly fogged. The thus obtained fog and other photographic properties of the emulsion can be maintained quite stably over a long period of time when a compound of the aforesaid general for mula (II) is incorporated into the emulsion in a proportion within the range from 0.01 to 30 g; per mole of the silver halide, or into another emulsion layer so that the amount of the compound in said layer comes within the said range, before the emulsion is coated, if necessary through a sub layer, on a suitable support such as, for example, paper, glass, cellulose acetate, or a polyester, polyamide, polystyrene, polycarbonate or the like synthetic resin film.

Typical examples of the compounds used in the present invention are as mentioned below.

Examples of the polyamine of the general formula (I):

(1) Diethylenetriamine (2) Triethylenetetramine (3) Tetraethylenepentamine (4) Pentaethylenehexamine (5) Hexaethyleneheptamine (6) Tripropylenetetramine (7) Dibutylenetriarnine (8) Spermine (9') Spermidine (10) N- (4-Aminobutyl) cadaverine Examples of the salt of a metal more electropositive than silver:

Gold compounds such as gold hydroxide, chloroauric acid and sodium chloroaurate.

Palladium compounds such as palladous potassium chloride and palladous ammonium chloride.

Platinum compounds such as potassium chloroplatinate and ammonium chloroplatinate.

Examples of the compound of the general formula (II):

(11) HOCH2-S OsNa (12) HOCHS OsNa aHn (13) HO-CHS OaNa 14) HO-CH-S OaNa (15) HO-CH-S OaNa (16) HOCHS OaNa no w (17) H0(CHz)2-S 03K 18) HO-(CH2)3S OaNa (19) HO-CH-S OaNa 20) HO-OHS OaNa S ;|Na

(21) H0CHS OaNa (22) HO-(OHzh-S OaNHa (23) HO-(CHDr-S 03K The aforesaid polyamine and salt of a metal more electropositive than silver which are used in the present invention are individually known as a fogging agent. The compounds of the general formula (II) can be synthesized, for example, in such a manner as described in the synthesis examples set forth below.

Synthesis Example 1 Synthesis of the exemplified compound (12): A solution of 10.4 g. of acidic sodium sulfite in ml. of water was incorporated with 11.4 g. of n-hexylaldehyde, and then shaken at room temperature together with 60 ml. of alcohol, and the resulting mixture was allowed to stand overnight. Thereafter, the mixture was heated under reflux 4 hours over a water bath, and the resulting pale yellow transparent reaction liquid was concentrated under reduced pressure to form white crystals. The thus formed crystals were dissolved in a water-methanol mixture and then precipitated by addition of ether. Subsequently, the precipitated crystals were recovered by filtration and then dried under reduced pressure to obtain 9.5 g. of pure white crystals, m.p. 300 C. or more.

Synthesis Example 2 Synthesis of the exemplified compound (13): A solution of 12.0 g. of acidic potassium sulfite in 30 ml. of pure water was incorporated with 10.6 g. of benzaldehyde. The resulting mixture was strongly shaken for 20 minutes, whereby white crystals precipitated with generation of heat. Subsequently, the mixture was allowed to stand overnight, and then the crystals were recovered by filtration. After sufliciently squeezing, the crystals were washed with 60 ml. of 8% alcohol and then with 100 ml. of petroleum ether, and thereafter dried under reduced pressure to obtain 15.8 g. of pure white crystals, m.p. 300 C. or more.

Other compounds of the general formula (II) can also be synthesized according to the procedures shown in the above-mentioned synthesis examples.

The silver halide emulsion used in the present invention may be an emulsion prepared according to any of the known methods, and examples of the silver halide include silver chlorobromide, silver bromide, silver chloroiodobromide and silver iodobromide. As the protective colloid in this case, gelatin is used in general. Alternatively, however, other hydrophilic organic colloids such as, for example, albumen, polyvinyl alcohol, etc., may also be used either singly or in the form of a mixture or in combination with gelatin.

Further, the above-mentioned emulsion may contain a spectral sensitizer such as a cyanine or merocyanine dye, a solarization promoter such as an inorganic or organic halide, an organic desensitizer, such as pynakryptol yellow, phenosafranine, etc., displaying a strong desensitizing action when added to a conventional negative-positive type silver halide emulsion, and a metal salt such as rhodium chloride. The emulsion may further contain a film hardener such as formaldehyde, a halogen-substituted fatty acid, e.g. mucobromic acid, or glyoxal, a wetting agent such as saponin or a salt of sulfated or alkylated polyethylene glycol ether, stabilizers, couplers and the like photographic additives.

The present invention is illustrated in more detail below with reference to examples, but it is needless to say that the modes of practice of the invention are not limited to the examples.

Example 1 An emulsion was prepared in the manner described below.

*A solution of 0.1 g. of RllCla.3H2O in 100 cc. of a 25% aqueous sodium chloride solution.

The liquid (II) was added at 50 C. to the liquid (I), and the liquid (III) was further added thereto with stirring. The resulting mixture was ripened at 50 C. for 40 minutes, incorporated with the liquid (IV) and then allowed to stand for minutes to prepare an emulsion.

The thus prepared emulsion was divided into emulsions (A) and (B), which were then individually incorporated with 10 mg. of triethylenetetramine. The emulsion (B) was further incorporated with 6 mg. of chloroauric acid. The emulsions (A) and (B) were individually ripened for 60 minutes and then cold set. After the setting, each emulsion was extruded to noodle form and then washed with running water for 30 minutes. The emulsion (B) was further divided into several emulsions, which were then individually incorporated with the exemplified compound shown in Table 1 and with formalin and saponin, coated on a transparent support and then dried to pre pare samples. On the other hand, the emulsion (A) was incorporated with formalin and saponin, coated on a transparent support and then dried to prepare a sample.

Each of the samples prepared in the above manner was exposed to a tungsten lamp through an optical wedge for sensitometry, and then subjected to ordinary development to measure the reversal speed and maximum density thereof. The development was carried out by use of a D-72 developer of Eastman Kodak Co. The stability test of each sample was carried out by allowing the sample to stand for 48 hours in an atmosphere kept at 50 C. and

6 tion which had been incorporated with the compounds of the aforesaid general formula (II) were scarcely changed in speed and lowered in maximum density even when subjected to the degradation test, and had quite stable and excellent photographic properties.

Example 2 An emulsion was prepared in the manner described below.

Gelatin g 16 Water cc 110 Sodium chloride ..g 4.8

Silver nitrate g 48 Water cc 400 (III) Potassium bromide g 34 Potassium iodide g 0.64 Rhodium chloride solution -cc-.. 1.2 Ammonia (28%) cc 40 Water cc 370 Glacial acetic acid The liquid (II) was added at 40 C. to the liquid (I), and the liquid (III) was further added thereto with stirring. The resulting mixture was ripened at 40 C. for 10 minutes, and then neutralized to a pH of 6.5 by addition of the liquid (IV) to prepare an emulsion.

The thus prepared emulsion was washed with water, incorporated with 12 g. of gelatin and then ripened at 50 C. for 10 minutes. Subsequently, the emulsion was divided into several emulsions, which were then individually incorporated with each of the exemplified compounds (5), (6), (7) and (8) in such amounts as shown in Table 2.

Each of the above-mentioned emulsions Was incorporated with a compound of the aforesaid general formula (II) in such amount as shown in Table 2 and then with formalin and saponin, coated on a transparent support RH. The results Obtained were as set forth 1n and drled to P p Samples Each Sample was exposed Table l. to a tungsten lamp through an optical wedge for sen- TABLE 1 After incubation at Immediately after 50 C. and 80% RH preparation for 48 hours Amount of compound Reversal Reversal incorpospeed speed Exemplified rated (mgJ (relative Maximum (relative Maximum Emulsion compound mole Ag) value) density value) density A Control (I) 0.05 0.04

Control (II) 4. 13 55 4. 09

As is clear from Table 1, no fog was obtained at all when triethylenetetramine was used singly [Control I)], whereas sufficient fog was obtained when it was used in combination with chloroauric acid [Control (II)]. However, the control (II) showed a marked desensitization when subjected to the stability test. In consitometry, and then subjected to ordinary development to 70 measure the reversal speed and maximum density theretrast thereto, the samples according to the present inven- 75 RH. The results obtained were as set forth in Table 2.

TABLE 2 After incubation at Immediately after 50 C. and 80% RH preparation for 48 hours Com- Reversal Reversal Compound of pound speed speed the formula Amount Amount the for- Amount (relative Maximum (relative Maximum (mg.) Gold compound (mg.) mula (II) (mg.) value) density value) density 5 Chloroaurie acid- 10 100 4. 03 48 3. 09 10 Gold hydroxide..- 98 4. 25 39 4.17 35 Sodium chloro- 7 93 4. 31 35 4. 25

aurate. 20 Chloroaurle acld 6 101 4. 02 51 4. do (11) 350 105 4.05 103 4. 03 10 Gold hydroxide-.- 3 800 102 4.03 99 4. 06 35 Sodium ch10ro- 7 (12) 450 100 4.03 98 4. 01

aura e. Chloroauric acid.. 6 (20) 1, 000 110 4. 00 105 4. 03 5 do 6 (12) 200 107 4.04 103 v 4.04

As is clear from Table 2, the samples according to the present invention had quite stable and excellent photographic properties.

What we claim is:

1. A direct positive light-sensitive silver halide photographic emulsion which contains silver halide grains fogged with from 1 to 200 mg. per mole of silver halide of a polyamine of the formula (1),

wherein n is an integer of 1 to 5, and Y is an alkylene group having 2 to 4 carbon atoms, provided that 2 or more Ys present in one molecule may be different alkylene groups and from 0.1 to 200 mg. per mole of silver halide of a salt of a metal more electropositive than silver, and a stabilizing amount from 0.1 to 30 g. per mole of silver halide of a compound of the formula (II),

wherein m is 0 or an integer of 1 to 8, R is a hydrogen atom, or an alkyl group having up to 17 carbon atoms, or an aryl group selected from the group consisting of a phenyl group and a napthyl which may be substituted with hydroxyl, carboxyl or sulfo groups and M is a cation.

2. A direct positive light-sensitive silver halide photographic emulsion as claimed in claim 1, wherein said polyamine is a member selected from the group consisting of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, tripropylenetetramine, dibutylenetriamine, spermine, spermidine and N-(4-aminobutyl)cadaverine.

3. A direct positive light-sensitive silver halide photographic emulsion as claimed in claim 1, wherein said metal is gold, palladium or platinum.

4. A direct positive light-sensitive silver halide photographic emulsion as claimed in claim 1, wherein the compound of the general formula (II) is a compound having any one of the following chemical structures:

HO(CH2)2S OaK, HO-(CHzh-S OaNa, HO-CH-S OaNa HO--CHS OaNa, HOCH--S OaNa, HO(CH2)4--S OaNHg References Cited UNITED STATES PATENTS 3/1970 Illingsworth 96108 7/1971 Haga et a1. 96109 RONALD H. SMITH, Primary Examiner W. H. LOVIE, JR., Assistant Examiner US. Cl. X.R. 96109